Comparing the efficacy of field treatments for actinic keratosis: a critical appraisal of a randomized trial in the New England Journal of Medicine.

AIM: Jansen et al. conducted a randomized trial to compare the efficacy of four field treatments for actinic keratosis (AK). SETTING AND DESIGN: This was a multicentre, single-blind, randomized trial conducted in the dermatology departments of four Netherlands hospitals. Patients were not blinded. The investigator who evaluated the trial outcome was blinded. STUDY EXPOSURE: This study included adult patients with at least five AKs on the face or vertex scalp. Patients were randomized to treatment with fluorouracil 5% cream, imiquimod 5% cream, methyl aminolaevulinate photodynamic therapy (MAL-PDT) or ingenol mebutate 0·015% gel. OUTCOMES: The primary outcome was whether patients had ≥ 75% reduction in AK count 12 months after treatment. RESULTS: In total 624 patients participated. The likelihood of having ≥ 75% reduction in AK count 12 months after treatment was significantly higher (twice as high or greater) for fluorouracil than for any other therapy. Approximately 75% of patients treated with fluorouracil experienced ≥ 75% reduction in AK count at 12 months. CONCLUSIONS: Jansen et al. conclude that 1 year after treatment, fluorouracil was significantly more effective at AK reduction than imiquimod, MAL-PDT or ingenol mebutate.

Spectrally smooth supercontinuum from 350 nm to 3 mum in sub-centimeter lengths of soft-glass photonic crystal fibers.

The conversion of light fields in photonic crystal fibers (PCFs) capitalizes on the dramatic enhancement of several optical nonlinearities. We present here spectrally smooth, highly broadband supercontinuum radiation in a short piece of high-nonlinearity soft-glass PCF. This supercontinuum spans several optical octaves, with a spectral range extending from 350 nm to beyond 3000 nm. The selection of an appropriate propagation-length determines the spectral quality of the supercontinuum generated. Experimentally, we clearly identify two regimes of nonlinear pulse transformation: when the fiber length is much shorter than the dispersion length, soliton propagation is not important and a symmetric supercontinuum spectrum arises from almost pure self-phase modulation. For longer fiber lengths the supercontinuum is formed by the breakup of multiple Raman-shifting solitons. In both regions very broad supercontinuum radiation is produced.

Asparaginase inhibition of adhesion of type 1-fimbriated and P-fimbriated Escherichia coli to epithelial cell receptors.

The 3D structures of Fim H and PapG proteins complexed with the host carbohydrate receptor demonstrate that both utilize binding-pocket asparagines for contact or stabilization with the carbohydrate. Pretreatment of whole bacteria with asparaginase resulted in decreased fimbriae-mediated attachment to urinary epithelial cells. Enzyme treatment of bacteria pre-adhered to epithelial cells removed more uropathogenic E. coli than the indigenous flora attached to them.